Health seeking behaviours and private sector delivery of care for non-communicable diseases in low- and middle-income countries: protocol for a systematic review

Introduction The burden of non-communicable diseases (NCDs) has increased substantially in low- and middle-income countries (LMICs), and adapting health service delivery models to address this remains a challenge. Many patients with NCD seek private care at different points in their encounters with the health system, but the determinants and outcomes of these choices are insufficiently understood. The proposed systematic review will help inform the governance of mixed health systems towards achieving the goal of universal health coverage. This protocol details our intended methodological and analytical approaches, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Methods and analysis Following the PRISMA approach, this systematic review will develop a descriptive synthesis of the determinants and outcomes of private healthcare utilisation for NCDs in LMICs. The databases Embase, Medline, Web of Science Core Collection, EconLit, Global Index Medicus and Google Scholar will be searched for relevant studies published in English between period 1 January 2010 and 30 June 2022 with additional searching of reference lists. The study selection process will involve a title-abstract and full-text review, guided by clearly defined inclusion and exclusion criteria. A quality and risk of bias assessment will be done for each study using the Mixed Methods Appraisal Tool. Ethics and dissemination Ethical approval is not required because this review is based on data collected from publicly available materials. The results will be published in a peer-reviewed journal and presented at related scientific events. PROSPERO registration number CRD42022340059

also unclear in the aims and introduction if this is all levels of healthcare (prevention, promotion, curative at the PHC level and hospital level)-although the levels are included in the search (see also comment about synthesis) There is good use of PRISMA and PICOT, although not clear if this is only adults, and there is mention of informal providers but not seen in search terms. This should be clarified In the determinants-interested if other population and community level factors.
In the analysis, there is note of a framework-is that the described organization or does this draw from any health system/utilization frameworks (ex. High quality health systems). The grouping while helpful, I think miss some of the aims and are a little confusing. For example, In describing determinants, I was unsure how health outcomes was not a consequence? I was also interested in why location (urban/rural) and level of care (for example, MI care versus PHC-based HTN) was captured and included in the synthesis as these reflect very different scope and levels of care The consequences are important but care will need to be taken if only descriptive versus comparisons to be able to determine causality of use of private (versus other) sector if that is part of the goals. Introduction (6) What is the authors' definition of the private sector? This needs to be clearly stated in the introduction as well.
(7) The authors should give a better indication of the existing evidence base on this topic, including any other systematic reviews. (8) Did the authors run preliminary searches in PROSPERO, JBI Evidence Synthesis and other electronic platforms to ensure that there are no other current or in-progress systematic reviews on this topic? Please expand on this in the protocol.

Methods
The authors should be more specific in their descriptions of selection criteria. (9) Page 5, line 47 -What is the definition of adults? (10) Page 5 -What are the main determinants of interest? Would the authors consider the wider socio-economic and political context (e.g., conflict-affected?) as well? Please expand on this. (11) Page 5, line 60 -What do the authors mean by "consequences of health seeking behaviour", please spell this out. If the authors also consider health outcomes as consequences, please list all the health outcomes of interest. (12) Need to provide justifications for a language restriction. (13) Given this is a comprehensive systematic review, I wonder if the authors will consider using database-specific filters to identify the experimental and observational studies of interest. For instance https://www.sign.ac.uk/what-we-do/methodology/searchfilters/ (14) Please revise the subsection 'Stakeholder consultation' planned for October 2022, as it is January 2023 just now. (15) Page 9, lines 45-46 -The authors describe "health outcomes" as determinants of health-seeking behaviour, however, these can also be consequences. This reiterates the importance of providing clear and precise definitions of key concepts used in the review. Please explain. (16) How the authors will synthesise evidence extracted from randomised and non-randomised studies. Please explain. Supplementary materials (17) PRISMA checklist should state the location where the item is reported, not if the item is reported. Please revise accordingly.

Reviewer 1
1. The authors describe a protocol for a systematic review of NCD care seeking in the private sector in LMICs. The review addresses an important and often ignored components of the care system and one which is increasingly used for management of NCDs in these countries. In the introductionthey state that ". Importantly, NCDs have an etiology linked to behavioral risk" while this is correct for some, there are other factors including environmental and genetic. It is important to recognize as strategies for prevention and control need to address multiple etiologies. There are a number of statements, which while correct, that need references such as the lack of inclusion of private sector in national NCD planning.
Response. We thank the reviewer for confirming the relevance of this systematic review and for drawing our attention to the statements in the introduction that need qualification and additional references, which we have duly added. 2. The aims are not quite as focused as the title and the introduction. The authors should consider focusing on private sector versus broader access if I am reading these aims correctly. The aims also include importantly private sector provider factors, but this is also not as clearly stated in the title and introduction or synthesis. It is also unclear in the aims and introduction if this is all levels of healthcare (prevention, promotion, curative at the PHC level and hospital level)-although the levels are included in the search (see also comment about synthesis).
Response. We agree and have clarified the review's objectives by adding to the introduction and aligning the research questions. We describe the levels and type of care in Table 1 and in subsection 'Inclusion/exclusion criteria'. We have also added references to the existing conceptual frameworks on which we draw.
"This study aims to synthesize the scattered evidence on how people with NCDs choose their healthcare providers in LMICs, and the outcomes of these choices, with a focus on the understudied private sector. In particular, we concentrate on the contextual and individual factors that influence provider choice, patterns of utilisation, quality of care and financial protection. We use the notion of the patient journey and draw on the the conceptual framework of facilitators and barriers to accessing healthcare. [21][22][23][24] 3. There is good use of PRISMA and PICOT, although not clear if this is only adults, and there is mention of informal providers but not seen in search terms. This should be clarified Response. We have specified in Table 1 that the population of interest are adults aged 18 years or older and we have listed the NCDs on which we focus. We have adopted a broad definition of private provider and exclude studies at the title-abstract screening and full-text review stages rather than filter for provider types and risk missing studies. See also response to Reviewer 2, comment 6. We have also clarified the levels of care and year on which the World Bank income groups are based. 4. In the analysis, there is note of a framework-is that the described organization or does this draw from any health system/utilization frameworks (ex. High quality health systems). The grouping while helpful, I think miss some of the aims and are a little confusing. For example, In describing determinants, I was unsure how health outcomes was not a consequence? I was also interested in why location (urban/rural) and level of care (for example, MI care versus PHC-based HTN) was captured and included in the synthesis as these reflect very different scope and levels of care. The consequences are important but care will need to be taken if only descriptive versus comparisons to be able to determine causality of use of private (versus other) sector if that is part of the goals.
Response. We acknowledge that our conceptual framework was not sufficiently clear, and we have addressed this by clarifying the review's aims and adding references to the existing frameworks on which we draw. See response to comment 2. We have also added a reference to the Donabedian model which helps conceptualise quality of care. We will outline our conceptual framework in more detail in the actual review rather than the protocol. See also response to Reviewer 2, comment 15.
"We will extract the determinants of selecting a health care provider, grouped into three categories: 1) individual factors such as demographics and health; 2) contextual factors such availability and accessibility of health care; and 3) perception of providers such as quality and competence. Lastly, we extract outcomes of selecting a health care provider, which we will group into three categories: 1) patterns of utilization including characteristics of patients and equity issues; 2) quality of care including the Donabedian model [40] domains of process and outcomes as well as patient satisfaction and empowerment; and 3) spending and financial protection as captured by indicators such as catastrophic health spending and impoverishment." p.8 Added references 40. Donadebian (1980) The definition of quality and approaches to its assessment, ISBN: 9780914904489 We appreciate the ambiguity around the way we used "health outcomes" as a determinant and reframed it as perception of providers. See also response to Reviewer 2, comment 10.
The reason we differentiate by location and level of care is because we anticipate that the studies we find will have a wide scope and different levels of care which cannot be directly compared, as you mention. However, we would like to keep the study broad by including a range of locations (urban/rural) and levels of care. It would be important to extract these factors so they can be described when analysing determinants and outcomes presented in different studies, and taken into consideration if any comparisons are made.

Reviewer 2
1. I would like the authors to be more specific in their descriptions of the review objectives.
Response. We agree and have clarified the review's objectives by adding to the introduction and aligning the research questions. We have also added references to the existing conceptual frameworks on which we draw. See also response to Reviewer 1, comment 2.
"This study aims to synthesize the scattered evidence on how people with NCDs choose their healthcare providers in LMICs, and the outcomes of these choices, with a focus on the understudied private sector. In particular, we concentrate on the contextual and individual factors that influence provider choice, patterns of utilisation, quality of care and financial protection. We use the notion of the patient journey and draw on exisiting conceptual frameworks of health seeking behaviour and the facilitators and barriers to accessing healthcare. [21][22][23][24] We thank the reviewer for the suggestion to look into Epistemonikos; we were not aware of this database and will use it for the introduction of our review where we will summarise previous systematic reviews.
4. Will the authors consider the use of electronic support tools (e.g., Covidence) to minimize bias in screening, quality assessment and data extraction? If yes, please add.
Response. We agree with the importance of minimizing bias in screening, quality assessment and data extraction. We considered several software tools and have now added the references that informed our decision.
"The articles resulting from the search will be screened by a team of two pairs ( Response. While space is of course limited in the abstract, we have now added more detail on this and clarified that the main analysis will be a descriptive synthesis and what results we will focus on. We will not perform a meta-analysis of quantitative data, which we acknowledge as a limitation and appears as a box with the abstract in BMJ Open. "The team will discuss and analyse the data extracted, which we will consolidate using a descriptive synthesis including a summary of the evidence, gaps, and limitations. As described above in the data extraction, we will synthesise the results into three categories of determinants of selecting a health care provider (individual factors, contextual factors and perception of providers) and three categories of outcomes of selecting a health care provider (patterns of utilization, quality of care, and spending and financial protection). We will also develop a synthesis of the results that concern the interaction of health seeking determinants and outcomes. A flow diagram of the inclusion/exclusion pathways and the descriptive statistics of the included studies and their outcomes will be developed to complement the analysis. We will not perform a meta-analysis because we expect highly diverse study characteristics, including design type, setting, intervention and outcome." p.9 "Strengths and limitations of this study We will not perform a meta-analysis because we expect highly diverse study characteristics, including design type, setting, intervention and outcome" p.2 6. What is the authors' definition of the private sector? This needs to be clearly stated in the introduction as well.
Response. We have a definition of the private sector in the sub-section 'Inclusion/exclusion criteria'.
"We use the World Health Organization's operational definition of the private health sector as the individuals and organizations that are neither owned nor directly controlled by governments, and are involved in the provision of health services (i.e. formal and informal providers as well as for-profit and non-profit entities.
[30]" p.5 7. The authors should give a better indication of the existing evidence base on this topic, including any other systematic reviews.
Response. We agree that the existing evidence base is important and include the rational for this review with the support of references in the introduction. We will discuss in dept the existing evidence in the actual review as opposed to the protocol given limited space and the emphasis here on methods. See also our responses to your comments 3 and 8.
8. Did the authors run preliminary searches in PROSPERO, JBI Evidence Synthesis and other electronic platforms to ensure that there are no other current or in-progress systematic reviews on this topic? Please expand on this in the protocol.
Response. We can confirm that we did run a preliminary search and appreciate the reminder to duly add this the protocol.
"This study is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and its extension for literature searches PRISMA-S.[27,28] PRISMA is a systematic approach to map and synthesise existing evidence, identify knowledge gaps and inform future research. This review was registered with PROSPERO (CRD42022340059) on 15 June 2022. We checked that there were no current or in-progress systematic reviews on the same topic by searching PROSPERO, the Research Registry, and the Open Science Framework." p.4 9. The authors should be more specific in their descriptions of selection criteria. What is the definition of adults?
Response. We have added a clearer definition of selection criteria, including on adults, to our subsection 'Inclusion/exclusion criteria' and Table 1. See also response to Reviewer 1, comment 3.
"We focus on adults aged 18 years of older..." p.5 10. What are the main determinants of interest? Would the authors consider the wider socio-economic and political context (e.g., conflict-affected?) as well? Please expand on this.
Response. We appreciate the opportunity to make this clearer and we have provided more detail on the main determinants of interest under the subsection 'Data extraction' (see also response to your comments 11, 15 and 16). This complements Table 2, which contains search elements and key terms.
"We will pilot and refine a data extraction framework including study details such as authors, title and year; and study characteristics such as research design, sample size, studied country, disease and provider type. We will also extract the determinants of selecting a health care provider, grouped into three categories: 1) individual factors such as demographics and health status; 2) contextual factors such availability and accessibility of health care; and 3) perception of providers such as quality and competence. Lastly, we extract outcomes of selecting a health care provider, which we will group into three categories: 1) patterns of utilization including characteristics of patients and equity issues; 2) quality of care including the Donabedian model[40] domains of process and outcomes as well as patient satisfaction and empowerment; and 3) spending and financial protection as captured by indicators such as catastrophic health spending and impoverishment." p.8 Added reference 40. Donadebian (1980) The definition of quality and approaches to its assessment, ISBN: 9780914904489 We will consider contextual factors to the extent they influence the selection of a health care provider (e.g. availability, convenience, affordability, accessibility, appropriateness of services). We will exclude irregular contextual circumstances (e.g., conflict, economic or political crises) because these are not generalizable (see sub-section 'Inclusion/exclusion criteria' p.5) 11. What do the authors mean by "consequences of health seeking behaviour", please spell this out. If the authors also consider health outcomes as consequences, please list all the health outcomes of interest. Response. We considered including all of the WHO languages (English, French, Spanish, Russian and Chinese) but do not have two fluent speakers for each language to independently screen and review the articles. We believe that translation software would do an imperfect job and have acknowledged this language restriction as a limitation. See also response to your comment 2 above.
13. Given this is a comprehensive systematic review, I wonder if the authors will consider using database-specific filters to identify the experimental and observational studies of interest. For instance: SIGN search filters Response. We thank you for the helpful suggestion and have considered database-specific filters, which would make the search more refined and return fewer results. However, every filter that is added has the risk of losing relevant studies since filters cannot capture 100% of the studies with a particular research design. As such, we prefer to search broadly for all study types with exclusion filters only for editorials and case reports. We will filter design type at the title-abstract and full-text review stages, which will take more time but ensure completeness.
14. Please revise the subsection 'Stakeholder consultation' planned for October 2022, as it is January 2023 just now.
Response. Thank you for pointing this out. We have dropped this subsection and noted our intentions elsewhere under the subsection 'Ethics and dissemination'.
"The results will be published in a topic relevant journal and presented at related scientific events attended by policy makers, academics and health care practitioners from LMICs, and later published in a topic relevant journal." p.9 15. The authors describe "health outcomes" as determinants of health-seeking behaviour, however, these can also be consequences. This reiterates the importance of providing clear and precise definitions of key concepts used in the review. Please explain.
Response. We agree with this point and view health care seeking from a provider as potentially a reiterative process with feedback loops (e.g. effectiveness of treatment and patient satisfaction influences future health seeking behaviour). We have made this clearer in the review's aims, research questions and data extraction. We have also added a reference to the Donabedian model which helps conceptualise quality of care as both a determinant and outcome. See also responses to comments 1 and 10 above.
16. How will the authors synthesise evidence extracted from randomised and non-randomised studies. Please explain.
Response. We have added more detail and clarified that the main analysis will be a descriptive synthesis and outlined the results that we will focus on. See response to comment 5 above. In the sub-section 'Quality assessment', we explain how we will use the Mixed Methods Appraisal Tool to assess methodological quality. This tool includes questions specific to different design types. For example, whether confounders are accounted for in the design and analysis of nonrandomised quantitative studies. Our assessment using MMAT will inform our synthesis of the randomised and non-randomised designs (e.g. highlighting the findings of higher quality studies

GENERAL COMMENTS
The authors have chosen to conduct a systematic review to fill an important gap in the knowledge needed to address the gap in capacity and delivery fo services to prevent, diagnose and manage the growing burden of NCDs in LMICs focusing on the often ignored role of the private sector. The methods are clearly described and appropriate. There were a few areas where more detail are needed . the authors should be more clear if and how they will focus on private sector. In addition, it would be helpful to understand if they were planning to use any health system and/or quality frameworks to understand barriers and facilitators for access, as well as the quality and equity of delivery of NCDs. In addition, it would be good to understand why mental health as a major cause of morbidity and contributing to mortality and with an enormous gap in capacity and delivery of care in LMICs. It would also be helpful to include a potential limitations.

VERSION 2 -AUTHOR RESPONSE
We are grateful to the reviewers for their careful reading of our revised paper and their valuable comments. We have responded below to each of the reviewers' points with new text added in red. We have also developed a diagram of our conceptual framework based on your helpful advice.

Reviewer 1
The authors have chosen to conduct a systematic review to fill an important gap in the knowledge needed to address the gap in capacity and delivery fo services to prevent, diagnose and manage the growing burden of NCDs in LMICs focusing on the often ignored role of the private sector. The methods are clearly described and appropriate. There were a few areas where more detail are needed. The authors should be more clear if and how they will focus on private sector. In addition, it would be helpful to understand if they were planning to use any health system and/or quality frameworks to understand barriers and facilitators for access, as well as the quality and equity of delivery of NCDs. In addition, it would be good to understand why mental health as a major cause of morbidity and contributing to mortality and with an enormous gap in capacity and delivery of care in LMICs. It would also be helpful to include a potential limitations Response. We thank the reviewer for reiterating the relevance of this systematic review and highlighting a few points that could be clearer.
Concerning our focus on the private sector, we explain in the introduction that we intend to synthesize evidence on how people with NCDs choose private health care providers in LMICs and the outcomes of these choices. In the exclusion/criteria section and appendix, we reference our use of the WHO's definition of the private health sector and how we will search for relevant articles. We have now made our focus on the private sector more explicit; the Introduction now contains the following: "This study aims to synthesize the scattered evidence on how people with NCDs choose their healthcare providers in LMICs, and the outcomes of these choices, in the understudied private sector. This will provide important new insights into the determinants and outcomes of private health care utilisation for NCDs in LMICs." We agree that a conceptual framework would help the reader understand our approach so we have developeda diagram describing our underlying framework and added references to the theoretical frameworks on which we draw: "We draw on existing theoretical approaches to health seeking behaviour and the facilitators and barriers to accessing healthcare. [21][22][23][24][25] Figure 1 depicts our conceptual framework of the non-linear interaction of the determinants and outcomes along the patient journey of seeking private health care for NCDs."p.5 accessing care are drivers of future health seeking. Please explain why these contextual factors are not of interest to your work.
Response. We thank the reviewer for reading our revised paper and drawing our attention to some remaining points that need clearification. ASSIA since it covers about 500 journals many of which are already indexed in the major databases we use. 85% of the ASSIA journals are also from the UK and the US, which is unlikely to help us increase the coverage of articles based on LMIC settings. We do not include SCOPUS because it does not have standardised indexing terms (i.e. emtree), nor support long search strategies. Furthermore, SCOPUS has considerable overlap with Embase which is also published by Elsevier and included in our search strategy. As shared in our response to the previous round of peer review, we will use Epistemonikos as per your suggestion to identify relevant systematic literature reviews. We will only include original research in the systematic review itself, but we will cite previous reviews in the introduction to summarise existing evidence and gaps.
(b and c) Regarding the outcomes and determinants of selecting a private health care provider, we agree that more detail could help the reader and we have developed a diagram representing our underlying conceptual framework and have added this as Figure 1 to our manuscript. It includes examples of determinants and outcomes of interest that are also more comprehensively listed in the search terms. We also agree that socio-cultural, economic and political contextual factors are important determinants of health-seeking in LMICs and we have added this helpful wording to the section of data extraction.

4
"We draw on existing theoretical approaches to health seeking behaviour and the facilitators and barriers to accessing healthcare. [21][22][23][24][25] Figure 1 depicts our conceptual framework of the non-linear interaction of the determinants and outcomes along the patient journey of seeking private health care for NCDs."p.5 "We will extract the determinants of selecting a health care provider, grouped into three categories: 1) individual factors such as demographics and health; 2) contextual factors such availability and accessibility of health care; and 3) perception of providers such as quality and competence. Lastly, we extract outcomes of selecting a health care provider, which we will group into three categories: 1) patterns of utilization including characteristics of patients and equity issues; 2) quality of care including the Donabedian model [25] domains of process and outcomes as well as patient satisfaction and empowerment; and 3) spending and financial protection as captured by indicators such as catastrophic health spending and impoverishment. We will also consider socio-cultural, economic and political contextual factors, which are important determinants of health-seeking in LMICs."p.9